Why do CPU fans have 3 pins?

A three pin connector is basically power (5/12 volt), ground, and signal. The signal wire measures how fast the fan is moving without any controls for the fan speed. With this type, fan speed is typically controlled by increasing or decreasing the voltage over the power wire.

Can I plug in 3 pin fan into 4 pin?

Please Note: You can connect a 3 Pin Fan to a 3 Pin or 4 Pin header on the motherboard. The fan will function normally no matter type of fan header is used.

What are the 4 wires on a computer fan?

A 4-wire fan has power, ground, a tach output, and a PWM-drive input. PWM, in brief, uses the relative width of pulses in a train of on-off pulses to adjust the level of power applied to the motor. A 2-wire fan is controlled by adjusting either the dc voltage or pulse width in low-frequency PWM.

Where do 3 pin fan connectors go?

As typical motherboard fan connector is a three or four-pin connector attached to the end of a PC fan’s wire. This is attached to the three or four-pin fan header on the motherboard. There’s no trick aside from lining up the notch on the connector with the guide on the header.

Do I need 4 pin or 3 pin fan?

The significant difference in practice is that 4-pin fans allow for RPM to change based on the need for cooling temperature, this reduces noise and power consumption. While 3-pin can control the voltage, but the voltage can’t turn to change the fan RPM at all and accurate as much as 4 pin fans.

Can I connect CPU fan to system fan?

If your CPU heatsink possesses more than one fan and your motherboard doesn’t have a CPU_OPT header, you’re free to use one of your SYS_FAN headers instead. Since CPU fans come with PWM, make sure you connect them to a 4-pin system fan header.

What is a SYS fan?

System Fan Header. Also known as SYS_FAN, and Chassis Fan, System Fan Header is used for connecting case fans to the motherboard. It provides the connected fans with voltage control, speed control and monitoring capability.

How do you wire a 4 pin PC fan?

The simplest PC fan requires just two wires – one wire provides power (12V), and the next wire is ground (0V)….4-wire fans explained.

PIN	WIRE COLOR	FUNCTION
1	Black	GND (0V)
2	Yellow	+12V
3	Green	Sense/Tach
4	Blue	Control/PWM

Can you run a 3 wire fan with 2 wires?

The 3 Pin fan will fit onto the 2 pin you just need to match the holes and the pins and see which two contacts make the fan function.

Can you control fan speed with 3 pin?

The speed of BOTH 3-pin and 4-pin fans can be controlled, but the method is different for the two types. For 3-pin fans, the connections to it are Ground to Pin #1, +VDC (varying) to Pin #2, and Speed signal on Pin #3.

Are most PC fans 4 pin?

PWM stands for pulse width modulation. A motherboard controls speed by intermittingly sending a current pulse to the fan. With a three pin connection, two are voltage and one is a speed sensor. Most motherboards have 4 pin for the cpu at least.

Does it matter where I plug in CPU fan?

CPU cooling fans should ALWAYS be plugged into the header that is specifically labeled “CPU Fan” and not “CPU Optional” or any other header.

Is SYS fan necessary?

You can safely use the computer without a sys_fan as long as the cpu and the other components run at temperatures inside their safety ranges, which is quite probable that they do, even without system fan, as long as the computer isn’t under heavy load or naturally power hungry.

Is SYS fan the same as CPU fan?

Basically, the fundamental difference between the System and the CPU fans is that the former is used for PC case/chassis ventilation where as the latter is used for the CPU cooling. Knowing the difference between the two is essential for installing ventilation for your desktop PC correctly.

How do 4 pin fans work?

How Does a 4-Pin PWM Fan Work? PWM can be used as a form of voltage control, and that’s exactly what it does for a PWM fan. The fan rotates according to the voltage supplied through the PWM control pin. It is also a way of providing better and smarter control for thermal management of the motherboard.